/*
silverPDF is sponsored by Aleyant Systems (http://www.aleyant.com)

silverPDF is based on PdfSharp (http://www.pdfsharp.net) and iTextSharp (http://itextsharp.sourceforge.net)

Developers: Ai_boy (aka Oleksii Okhrymenko)

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:

The above information and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR SPONSORS
BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

*/
#region PDFsharp - A .NET library for processing PDF
//
// Authors:
//   Stefan Lange (mailto:Stefan.Lange@pdfsharp.com)
//
// Copyright (c) 2005-2008 empira Software GmbH, Cologne (Germany)
//
// http://www.pdfsharp.com
// http://sourceforge.net/projects/pdfsharp
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
// DEALINGS IN THE SOFTWARE.
#endregion

using System;
using System.Diagnostics;
using System.Globalization;
using System.Text;
using System.IO;
#if GDI
using System.Drawing;
using System.Drawing.Drawing2D;
#endif
#if WPF
using System.Windows.Media;
#endif
using PdfSharp.Internal;
using PdfSharp.Pdf;
using PdfSharp.Pdf.Advanced;
using PdfSharp.Pdf.Internal;

namespace PdfSharp.Drawing.Pdf
{
  // TODO: update the following text
  //
  // In PDF the current transformation matrix (CTM) can only be modified, but not set. The XGraphics
  // object allows to set the transformation matrix, which leads to a problem. In PDF the only way
  // to reset the CTM to its original value is to save and restore the PDF graphics state. Don't try
  // to keep track of every modification and then reset the CTM by multiplying with the inverse matrix
  // of the product of all modifications. PDFlib uses this 'trick', but it does not work. Because of
  // rounding errors everything on the PDF page looks sloping after some resets. Saving and restoring
  // the graphics state is the only possible way to reset the CTM, but because the PDF restore operator
  // 'Q' resets not only the CTM but all other graphics state values, we have to implement our own 
  // graphics state management. This is apparently the only safe way to give the XGrahics users the 
  // illusion that they can arbitrarily set the transformation matrix.
  // 
  // The current implementation is just a draft. Save/Restore works only once and clipping is not
  // correctly restored in some cases.

  /// <summary>
  /// Represents the current PDF graphics state.
  /// </summary>
  internal sealed class PdfGraphicsState : ICloneable
  {
    public PdfGraphicsState(XGraphicsPdfRenderer renderer)
    {
      this.renderer = renderer;
    }
    XGraphicsPdfRenderer renderer;

    public PdfGraphicsState Clone()
    {
      PdfGraphicsState state = (PdfGraphicsState)MemberwiseClone();
      return state;
    }

    object ICloneable.Clone()
    {
      return Clone();
    }

    internal int Level;

    internal InternalGraphicsState InternalState;

    public void PushState()
    {
      //BeginGraphic
      this.renderer.Append("q/n");
    }

    public void PopState()
    {
      //BeginGraphic
      this.renderer.Append("Q/n");
    }

    #region Stroke

    double realizedLineWith = -1;
    int realizedLineCap = -1;
    int realizedLineJoin = -1;
    double realizedMiterLimit = -1;
    XDashStyle realizedDashStyle = (XDashStyle)(-1);
    string realizedDashPattern;
    XColor realizedStrokeColor = XColor.Empty;

    public void RealizePen(XPen pen, PdfColorMode colorMode)
    {
      XColor color = pen.Color;
      color = ColorSpaceHelper.EnsureColorMode(colorMode, color);

      if (this.realizedLineWith != pen.width)
      {
        this.renderer.AppendFormat("{0:0.###} w\n", pen.width);
        this.realizedLineWith = pen.width;
      }

      if (this.realizedLineCap != (int)pen.lineCap)
      {
        this.renderer.AppendFormat("{0} J\n", (int)pen.lineCap);
        this.realizedLineCap = (int)pen.lineCap;
      }

      if (this.realizedLineJoin != (int)pen.lineJoin)
      {
        this.renderer.AppendFormat("{0} j\n", (int)pen.lineJoin);
        this.realizedLineJoin = (int)pen.lineJoin;
      }

      if (this.realizedLineCap == (int)XLineJoin.Miter)
      {
        if (this.realizedMiterLimit != (int)pen.miterLimit && (int)pen.miterLimit != 0)
        {
          this.renderer.AppendFormat("{0} M\n", (int)pen.miterLimit);
          this.realizedMiterLimit = (int)pen.miterLimit;
        }
      }

      if (this.realizedDashStyle != pen.dashStyle || pen.dashStyle == XDashStyle.Custom)
      {
        double dot = pen.Width;
        double dash = 3 * dot;

        // Line width 0 is not recommended but valid
        XDashStyle dashStyle = pen.DashStyle;
        if (dot == 0)
          dashStyle = XDashStyle.Solid;

        switch (dashStyle)
        {
          case XDashStyle.Solid:
            this.renderer.Append("[]0 d\n");
            break;

          case XDashStyle.Dash:
            this.renderer.AppendFormat("[{0:0.##} {1:0.##}]0 d\n", dash, dot);
            break;

          case XDashStyle.Dot:
            this.renderer.AppendFormat("[{0:0.##}]0 d\n", dot);
            break;

          case XDashStyle.DashDot:
            this.renderer.AppendFormat("[{0:0.##} {1:0.##} {1:0.##} {1:0.##}]0 d\n", dash, dot);
            break;

          case XDashStyle.DashDotDot:
            this.renderer.AppendFormat("[{0:0.##} {1:0.##} {1:0.##} {1:0.##} {1:0.##} {1:0.##}]0 d\n", dash, dot);
            break;

          case XDashStyle.Custom:
            {
              StringBuilder pdf = new StringBuilder("[", 256);
              int len = pen.dashPattern == null ? 0 : pen.dashPattern.Length;
              for (int idx = 0; idx < len; idx++)
              {
                if (idx > 0)
                  pdf.Append(' ');
                pdf.Append(PdfEncoders.ToString(pen.dashPattern[idx] * pen.width));
              }
              // Make an even number of values look like in GDI+
              if (len > 0 && len % 2 == 1)
              {
                pdf.Append(' ');
                pdf.Append(PdfEncoders.ToString(0.2 * pen.width));
              }
              pdf.AppendFormat(CultureInfo.InvariantCulture, "]{0:0.###} d\n", pen.dashOffset * pen.width);
              string pattern = pdf.ToString();

              // BUG: drice2@ageone.de reported a realizing problem
              // HACK: I romove the if clause
              //if (this.realizedDashPattern != pattern)
              {
                this.realizedDashPattern = pattern;
                this.renderer.Append(pattern);
              }
            }
            break;
        }
        this.realizedDashStyle = dashStyle;
      }

      if (colorMode != PdfColorMode.Cmyk)
      {
        if (this.realizedStrokeColor.Rgb != color.Rgb)
        {
          this.renderer.Append(PdfEncoders.ToString(color, PdfColorMode.Rgb));
          this.renderer.Append(" RG\n");
        }
      }
      else
      {
        if (!ColorSpaceHelper.IsEqualCmyk(this.realizedStrokeColor, color))
        {
          this.renderer.Append(PdfEncoders.ToString(color, PdfColorMode.Cmyk));
          this.renderer.Append(" K\n");
        }
      }

      if (this.renderer.Owner.Version >= 14 && this.realizedStrokeColor.A != color.A)
      {
        PdfExtGState extGState = this.renderer.Owner.ExtGStateTable.GetExtGStateStroke(color.A);
        string gs = this.renderer.Resources.AddExtGState(extGState);
        this.renderer.AppendFormat("{0} gs\n", gs);

        // Must create transparany group
        if (this.renderer.page != null && color.A < 1)
          this.renderer.page.transparencyUsed = true;
      }
      this.realizedStrokeColor = color;
    }

    #endregion

    #region Fill

    XColor realizedFillColor = XColor.Empty;

    public void RealizeBrush(XBrush brush, PdfColorMode colorMode)
    {
      if (brush is XSolidBrush)
      {
        XColor color = ((XSolidBrush)brush).Color;
        color = ColorSpaceHelper.EnsureColorMode(colorMode, color);

        if (colorMode != PdfColorMode.Cmyk)
        {
          if (this.realizedFillColor.Rgb != color.Rgb)
          {
            this.renderer.Append(PdfEncoders.ToString(color, PdfColorMode.Rgb));
            this.renderer.Append(" rg\n");
          }
        }
        else
        {
          if (!ColorSpaceHelper.IsEqualCmyk(this.realizedFillColor, color))
          {
            this.renderer.Append(PdfEncoders.ToString(color, PdfColorMode.Cmyk));
            this.renderer.Append(" k\n");
          }
        }

        if (this.renderer.Owner.Version >= 14 && this.realizedFillColor.A != color.A)
        {
          PdfExtGState extGState = this.renderer.Owner.ExtGStateTable.GetExtGStateNonStroke(color.A);
          string gs = this.renderer.Resources.AddExtGState(extGState);
          this.renderer.AppendFormat("{0} gs\n", gs);

          // Must create transparany group
          if (this.renderer.page != null && color.A < 1)
            this.renderer.page.transparencyUsed = true;
        }
        this.realizedFillColor = color;
      }
      else if (brush is XLinearGradientBrush)
      {
        XMatrix matrix = this.renderer.defaultViewMatrix;
        matrix.Prepend(this.Transform);
        PdfShadingPattern pattern = new PdfShadingPattern(this.renderer.Owner);
        pattern.SetupFromBrush((XLinearGradientBrush)brush, matrix);
        string name = this.renderer.Resources.AddPattern(pattern);
        this.renderer.AppendFormat("/Pattern cs\n", name);
        this.renderer.AppendFormat("{0} scn\n", name);

        // Invalidate fill color
        this.realizedFillColor = XColor.Empty;
      }
    }
    #endregion

    #region Text

    internal PdfFont realizedFont;
    string realizedFontName = String.Empty;
    double realizedFontSize = 0;

    public void RealizeFont(XFont font, XBrush brush, int renderMode)
    {
      // So far rendering mode 0 only
      RealizeBrush(brush, this.renderer.colorMode); // this.renderer.page.document.Options.ColorMode);

      this.realizedFont = null;
      string fontName = this.renderer.GetFontName(font, out this.realizedFont);
      if (fontName != this.realizedFontName || this.realizedFontSize != font.Size)
      {
        if (this.renderer.Gfx.PageDirection == XPageDirection.Downwards)
          this.renderer.AppendFormat("{0} {1:0.###} Tf\n", fontName, -font.Size);
        else
          this.renderer.AppendFormat("{0} {1:0.###} Tf\n", fontName, font.Size);

        this.realizedFontName = fontName;
        this.realizedFontSize = font.Size;
      }
    }

    public XPoint realizedTextPosition = new XPoint();

    #endregion

    #region Transformation

    /// <summary>
    /// The realized current transformation matrix.
    /// </summary>
    XMatrix realizedCtm = XMatrix.Identity;

    /// <summary>
    /// The unrealized current transformation matrix.
    /// </summary>
    XMatrix unrealizedCtm = XMatrix.Identity;

    /// <summary>
    /// A flag indicating whether the CTM must be realized.
    /// </summary>
    public bool MustRealizeCtm;

    public XMatrix Transform
    {
      get
      {
        if (this.MustRealizeCtm)
        {
          XMatrix matrix = this.realizedCtm;
          matrix.Prepend(this.unrealizedCtm);
          return matrix;
        }
        return this.realizedCtm;
      }
      set
      {
        XMatrix matrix = this.realizedCtm;
        matrix.Invert();
        matrix.Prepend(value);
        this.unrealizedCtm = matrix;
        this.MustRealizeCtm = !this.unrealizedCtm.IsIdentity;
      }
    }

    /// <summary>
    /// Modifies the current transformation matrix.
    /// </summary>
    public void MultiplyTransform(XMatrix matrix, XMatrixOrder order)
    {
      if (!matrix.IsIdentity)
      {
        this.MustRealizeCtm = true;
        this.unrealizedCtm.Multiply(matrix, order);
      }
    }

    /// <summary>
    /// Realizes the CTM.
    /// </summary>
    public void RealizeCtm()
    {
      if (this.MustRealizeCtm)
      {
        Debug.Assert(!this.unrealizedCtm.IsIdentity, "mrCtm is unnecessarily set.");

        double[] matrix = this.unrealizedCtm.GetElements();
        // Up to six decimal digits to prevent round up problems
        this.renderer.AppendFormat("{0:0.######} {1:0.######} {2:0.######} {3:0.######} {4:0.######} {5:0.######} cm\n",
          matrix[0], matrix[1], matrix[2], matrix[3], matrix[4], matrix[5]);

        this.realizedCtm.Prepend(this.unrealizedCtm);
        this.unrealizedCtm = XMatrix.Identity;
        this.MustRealizeCtm = false;
      }
    }

    #endregion

    #region Clip Path

    public void SetAndRealizeClipRect(XRect clipRect)
    {
      XGraphicsPath clipPath = new XGraphicsPath();
      clipPath.AddRectangle(clipRect);
      RealizeClipPath(clipPath);
    }

    public void SetAndRealizeClipPath(XGraphicsPath clipPath)
    {
      RealizeClipPath(clipPath);
    }

    void RealizeClipPath(XGraphicsPath clipPath)
    {
      this.renderer.BeginGraphic();
      RealizeCtm();
#if GDI && !WPF
      this.renderer.AppendPath(clipPath.gdipPath);
#endif
#if WPF &&!GDI
      this.renderer.AppendPath(clipPath.pathGeometry);
#endif
#if WPF && GDI
      if (this.renderer.Gfx.targetContext == XGraphicTargetContext.GDI)
      {
        this.renderer.AppendPath(clipPath.gdipPath);
      }
      else
      {
        this.renderer.AppendPath(clipPath.pathGeometry);
      }
#endif
      if (clipPath.FillMode == XFillMode.Winding)
        this.renderer.Append("W n\n");
      else
        this.renderer.Append("W* n\n");
    }

    #endregion
  }
}
